From almost total obscurity, the Internet swiftly leapt into our lives. Once an arcane communication medium for academics and researchers, it now sustains almost any human activity you can imagine, from shopping to sex, from research to rebellion. We use it to keep in touch with friends and coworkers, search for bargains, conduct research, exchange information, meet strangers, hatch conspiracies, and even – as I recently learned – talk to animals. Koko, the mountain gorilla who has been learning American Sign Language from Penny Patterson for more than 20 years, has now participated in live Internet chats. People from all over the world logged into the chat room to ask questions and hear Koko's views on motherhood, pets, food preferences, friendship, love, and the future. She was not in the best mood, having just had a tiff with her mate, Ndume, and she shared her annoyance with the crowd by referring to him derisively as toilet, which is her word for bad.

The Internet explosion happened so rapidly that we have not had much time to step back from the medium and look at it more systematically, as a new environment that can have potent effects on our behavior. It is a place where we humans are acting and interacting rather strangely at times. Sometimes its effects seem to be quite positive, but sometimes, we do things online that we might never do in any other environment, and that we regret later.